On your first cycle sust 250 will give you some nice gains, but just to reiterate what some other have said: the way you eat and train will determine just what you can get out of it. To answer the other part of your question, sust is a strong steriod but are a few stronger ones (d-bol, anadrol). From my experience sust 250 is one of the easiest roids to come across. Good luck